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Background
The skin is the largest organ in the body. We don't often think of the skin as an organ, but it provides important functions besides providing us our beauty. It is one of first immune barriers to the outside world and is an active site of the immune system processing and destroying foreign proteins and molecules. Unfortunately, because of its large size, it is subject to the brutalizing rays of the sun and other environmental challenges, accounting for many diseases as well as skin cancers. Pathologists who specialize in the diagnosis of skin diseases are called dermatopathologists. They are required to have training in clinical dermatology as well as pathology in order to completely understand how skin diseases present in the patient.
- Acantholytic Dyskeratoses
- Acanthomas
- Cysts (Epidermal Inclusion Cysts, Sebaceous Cysts, Pilar Cysts)
- Collagen, elastic fibers, and dermal diseases (Scar, Morphea)
- Ectodermal Dysplasia
- Epidermolytic Hyperkeratoses
- Epidermal Nevus (ILVEN)
- Gangrene
Hair and Nails (Alopecia, Baldness) - Histiocytoses (Langerhans and Non-Langerhans)
- Ichthyoses
- Keratodermas
- Keratoses (Actinic Keratosis, Seborrheic Keratosis)
- Panniculitis (Inflammation of the fat)
- Perforating Disorders
- Photosensitive Disorders
Pigmented and Hypopigmented Lesions (Moles, Dysplastic Nevus, Melanoma, Vitiligo) - Porokeratosis
Rashes and Blistering Diseases (Bullous Pemphigoid, Pemphigus) Skin Cancers and Tumors of the Skin Adnexal Epithelium (Basal Cell Carcinoma, Squamous Cell Carcinoma) - Skin Lymphomas (Mycosis Fungoides, CTCL)
- Skin Pseudolymphomas
- Skin Syndromes (Cowden syndrome, Turban Tumor Syndrome)
- Xeroderma pigmentosum
Anatomy and Histology
To understand the disease process that affect the skin, one must have a clear understanding of the anatomy and histology of the skin. Some of these terms are found in The Cell section. Other terms specific the skin may be found through these following links.
Basement membrane zone-Anchoring Complex
Epidermis-Keratinocyte
Dermis and Connective Tissue
Immunofluorescence
Matrix Metalloproteinases
Skeletal Muscle occurring in the skinThe embryonic and fetal skin is a dynamic interface involving interactions with numerous oncogenes. Bcl-2 and bax genes are members of the bcl-2 gene family, involved in regulation of apoptosis. Bcl-2 protein is anti-apoptotic while bax is a cell death promoter. Recently, it has been shown that in the earliest development, these two proteins localize to the epidermal portion of the hair follicle. With development, bax becomes localized to areas where the hair canal is excavated and keratinization and holocrine secretion is initiated. Bcl-2 is expressed in the follicular papilla. Dendritic cells scattered throughout the basal and immediate suprabasal interfollicular epidermis and outer root sheath of the developing hair bulge express bcl-2 and HMB-45.
OUTLINE
Laboratory/Radiologic/Other Diagnostic Testing Gross Appearance and Clinical Variants Histopathological Features and Variants Commonly Used Terms Internet Links
HISTOPATHOLOGY CHARACTERIZATION ELDERY PATIENTS Skin pathology findings in a cohort of 1500 adult and elderly subjects.
Siragusa M, Schepis C, Palazzo R, Fabrizi G, Guarneri B, Del Gracco S, Spada RS, Ferri R.
Department of Neurology, Oasi Institute for Research and Prevention of Mental Retardation, Troina, Italy.
Int J Dermatol 1999 May;38(5):361-6 Abstract quote
BACKGROUND: No extensive studies are available in the literature on the eventual skin pathology induced by neurologic or systemic diseases in elderly individuals. Other factors, such as health and hygiene, socioeconomic status, and climate can also play an important role.
METHODS: Fifteen-hundred subjects (886 women and 614 men; mean age, 67.8 years; range, 39-90 years) were admitted to the Department of Geriatrics at the Oasi Institute between 1992 and 1997; all these subjects were carefully evaluated from a dermatologic point of view. Each subject underwent specialist examinations, routine blood analyses, thoracic X-rays, cerebral computerized tomography (CT) scan, and magnetic resonance imaging (MRI) when appropriate. A group of subjects without significant neurologic or systemic disease, comprising 116 women and 60 men (mean age, 64.5 years; range, range, 40-90 years), was selected and used as a normal control group. Subsequently, our attention was focused on the eventual presence of the following neurologic diseases: Alzheimer-type dementia, vascular dementia, mixed-type dementia, subcortical dementia, Parkinson's disease, vascular brain disease, hemiplegia, etc. Thus, different subgroups were formed on the basis of such diagnostic categories and the frequency of skin pathology in each subgroup was evaluated.
RESULTS: Of the 1500 subjects, 1439 stated that they had never been affected by dermatologic disease. No statistically significant difference in frequency of skin pathology was found between normal controls and the different patient subgroups. Unsuspected and singular dermatoses were found, however, such as paraneoplastic syndromes, idiopathic tripe palms, white fibrous papulosis of the neck as an expression of photoaging, conditions induced by former popular traditions of Sicilian culture (anetoderma secondary to the application of Hirudo medicinalis and erythema ab igne), pigmented dermatoses never described before in Italy (prurigo pigmentosa and friction amyloidosis), and nail abnormalities (atypical half-and-half nail, and dyschromic nail changes in multiple system atrophy and in hemiplegia).
CONCLUSIONS: The dermatologic screening performed in 1500 patients revealed several unexpected diagnoses and some original observations. Some rare dermatoses were described and certain hypotheses were suggested to explain the peculiar dyschromic changes of the fingernails in multiple system atrophy, the atypical cases of half-and-half nail, and the so-called idiopathic tripe palms associated with psoriasis.
TELEPATHOLOGY TRANSPLANTATION
The Pathology of Full-thickness Cadaver Skin Transplant for Large Abdominal Defects: A Proposed Grading System for Skin Allograft Acute Rejection.
Bejarano PA, Levi D, Nassiri M, Vincek V, Garcia M, Weppler D, Selvaggi G, Kato T, Tzakis A.
Departments of *Pathology and daggerSurgery, University of Miami School of Medicine/Jackson Memorial Hospital, Miami, FL.
Am J Surg Pathol. 2004 May;28(5):670-675. Abstract quote
Closure of large abdominal defects after extensive abdominal surgery is a major technical surgical problem. Failure to close the abdomen leaves the patient at risk for grave complications. Full-thickness abdominal wall skin transplantation appears to solve this problem.
This is the first time that detailed histopathologic features of skin abdominal wall transplantation from cadaver donors are described. Five adults and four children underwent 10 transplants because of large abdominal wall defects. Twenty-two posttransplantation skin specimens were evaluated during a mean follow-up of 23.5 weeks, and the findings were compared with the clinical appearance of the skin. Rejection was manifested as a maculopapular rash.
The histologic features were categorized as perivascular infiltrates, epidermal changes, and stromal changes. A grading system is proposed based on the number of cases encountered: No rejection, grade 0 (n = 9): No perivascular infiltrates. Indeterminate for rejection, grade 1 (n = 2): Up to 10% of vessels show infiltrates of small lymphocytes. No eosinophils, large lymphocytes, spongiosis, epidermal, or stromal inflammation are seen. Mild rejection, grade 2 (n = 5): 11% to 50% of vessels are infiltrated by small lymphocytes. Eosinophils and mild spongiosis may or may not be present. No epidermal infiltrates, stromal infiltrates, or large lymphocytes are seen. Moderate rejection, grade 3 (n = 4): Greater than 50% of vessels show lymphocytic infiltrates that may be accompanied by epidermal and stromal inflammation. Spongiosis is absent or mild. Endothelial plumping, eosinophils, and large lymphocytes may be seen. Severe rejection, grade 4 (n = 2): Greater than 50% of vessels show infiltrates, but different from moderate rejection, there is dyskeratosis and the epidermis shows heavier lymphocytic infiltrates and moderate to severe spongiosis. The stroma shows infiltrates extending into the base of the epidermis. Endothelial plumping, eosinophils, and large lymphocytes are present.
The mean number of weeks after transplantation for the development of clearcut rejection (grades 2-4) was 8.36. Among the 9 nonrejection cases, 4 specimens from 3 patients had thrombosis of the vessels feeding the graft. A grading system serves to better assess skin allograft rejection.Am J Dermatopathol 2001;23:1-7.
Henry JB. Clinical Diagnosis and Management by Laboratory Methods. Twentieth Edition. WB Saunders. 2001.
Rosai J. Ackerman's Surgical Pathology. Ninth Edition. Mosby 2004.
Sternberg S. Diagnostic Surgical Pathology. Fourth Edition. Lipincott Williams and Wilkins 2004.
Robbins Pathologic Basis of Disease. Seventh Edition. WB Saunders 2005.
DeMay RM. The Art and Science of Cytopathology. Volume 1 and 2. ASCP Press. 1996.
Weedon D. Weedon's Skin Pathology Second Edition. Churchill Livingstone. 2002
Fitzpatrick's Dermatology in General Medicine. 5th Edition. McGraw-Hill. 1999.
Weiss SW and Goldblum JR. Enzinger and Weiss's Soft Tissue Tumors. Fourth Edition. Mosby 2001.
Gross Clinical Description Characterization Blister Vesicle or bulla Bulla Fluid-filled area greater than 5 mm across Dimples Invagination of the skin Crust Deposit of inspissated material which may contain plasma (red cells, white cells, or both) Exanthem Skin eruption occurring as a symptom of a general disease, usually an infectious process Excoriation Traumatically induced lesion leading to breakage of the epidermis Lichenification Thickened skin formed by repeated rubbing Linear Following a line, may follow Lines of Blaschko Macule Flat and circumscribed area of any size Nodule Elevated solid area greater than 5 mm across Onycholysis Loss of integrity of the nail substance Papule Elevated solid area 5 mm or less Photosensitivity Lesions are distributed in areas exposed to ultraviolet radiation Plaque Elevated flat topped lesion, usually greater than 5 mm across Pruritis Itching Punch Biopsy A type of biopsy where an instrument punches out a small cylinder of skin, usually ranging from 2 to 6 millimeters Pustule Pus filled raised area Scale-Crust Combination of scale and crust Shave Biopsy A type of biopsy where a superficial shave of the skin is performed Sporotrichoid Spread Lymphangitic spread with nodules that ascend proximally along lymphatic vessels Wheal Transient raised erythematous area which blanches
Clinical Signs Characterization Deck Chair Sign Sparing of the creases in skin folds in an erythroderma consisting of confluent flat-topped pink papules and associated with a peripheral eosinophilia
Occurs in Papuloerythroderma of Ofuji
Nazarro's sign Spiky hair-like collections of paraproteins occurring on the skin of the nose of multiple myeloma patients
Microscopic Terms Characterization Acantholysis Dyscohesion between keratinocytes from loss of the intercellular connections Acanthosis Hyperplastic epidermis Dyskeratosis Abnormal keratinization Erosion Incomplete loss of the epidermis Exocytosis Inflammatory cells infiltrating the epidermis Granuloma Collection of epithelioid histiocytes Hyperkeratosis Hyperplasia of the stratum corneum leading to a clinical scale Papillomatosis Hyperplasia of the papillary dermis Parakeratosis Retention of nuclei within the stratum corneum. It is indicative of prior spongiosis. It is a normal finding in mucous membranes Spongiosis Intercellular edema within the epidermis Ulceration Complete loss of the epidermis which extends into the dermis and may extend into the subcutaneous fat Vacuolization Vacuoles within or adjacent to cells. Usually refers to the area of the dermal-epidermal junction
Basic Principles of Disease
Learn the basic disease classifications of cancers, infections, and inflammation
Commonly Used Terms
This is a glossary of terms often found in a pathology report.Diagnostic Process
Learn how a pathologist makes a diagnosis using a microscopeSurgical Pathology Report
Examine an actual biopsy report to understand what each section meansSpecial Stains
Understand the tools the pathologist utilizes to aid in the diagnosisHow Accurate is My Report?
Pathologists actively oversee every area of the laboratory to ensure your report is
accurate
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Recent teaching cases and lectures presented in conferences
Last Updated April 22, 2005
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